Casing for an electric lamp



FIG. 1 is a front elevational view of a casing for an electric lamp embodying my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is an elevational view of one side thereof;

FIG. 4 is an elevational view of the other side thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof. 

The ornamental design for a casing for an electric lamp, as shown and described. 